For example: Lets say we have a database with all the soccer games (outcomes, player scores, etc.) and now we want a tool, that extracts the answer to natural language questions from this database

I suppose we could not simply ingest this database into watson QA, since it contains nearly nohing else than raw data. but how could I make use of watson services to understand the intetion of the question and let watson help me figure out what piece of data I need to extract from the database.

2 answers

You would likely want to use the Watson Conversation service. The intent would be the information they want. "Who won" and then the entities you would extract would be the teams and potentially the date if there are multiple instances.
"Who wont the world series in 2016"
Intent: Who won
Entity: world series, 2016